Create a new profile as a test to check if your current profile is causing the problems.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer some files from an existing profile to the new profile, but be careful not to copy corrupted files.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Which security software (firewall, anti-virus) do you have?

Try to boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.

Thanks cor-el for the prompt reply. Appreciated it. I have tried creating a new profile and deleted the old one at the same time but it didn't help to solve the problem.

I have AVG 2013 free edition installed. have since disabled it to no effect too. I will try booting Win in safe mode and try again later.

BTW, i have no problem running FF smoothly on previous version until FF is updated to 18.0.1... Not sure whether any other users have similar problems?

OK, just tried the safe mode Win 7. Firefox still hang a few seconds when loading pages or open new tab. When it hangs, the browser is not responsive to any clicks.

Are there any plugin used on pages if the freeze happens?

You can check for outdated plugins.

• http://www.mozilla.org/plugincheck/

Try to reset (power off/on) the router.

I was loading these few pages: www.google.com; www.facebook.com; www.twitter.com; www.bbc.com Initially I was suspecting the flash plugin, but even after uninstalling, the problem still exists. I have no problems loading pages from other browsers. Used fibre cable internet on 2 different locations. It's a sad day to lose Firefox...

Firefox 19 gets released in about two weeks. So you could try out the current beta version to see if the issue remains: http://www.mozilla.org/en-US/firefox/beta/

Hello all, I have tried uninstall the FF, then reinstall FF18.0.1 without any success in solving the problem. Tried FF 19 and Aurora too. They are having the same problems too. I have make a full scan on my system for viruses and malwares and found nothing. Tried restoring to older version of FF and the problem exists too even in safe mode. I have ran out of ideas to solve this. Is a full system recovery that's what it takes to get my favorite browser back to life? Sigh...

I experienced the exact same problem since a few days. Clicking a link (for instance bbc.com) resulted in a 5-10 second freeze of the Firefox browser (v. 18.0.2, Windows 7 x86). So I checked what software/plugins were updated in the past few days, and I came to the conclusion that the Shockwave Flash plugin updated to version 11.6.602.168. (So yes, it is up to date now.)

Disabling this plugin solved the issue completely. I checked a few times between enabling and disabling. Sor for some reason, version 11.6.602.168 of Shockwave Flash causes troubles.

I'm leaving it disable for now. But is a pain, because numerous websites need flash. I really hope this will be fixed in either Firefox or the plugin itself.

Hi PHJJ0042. Thanks for your post. I have disabled the Flash Plug-in with no effect to the slugginess (freezes) to the browser. There must be something wrong somewhere. I reckon a clean re-installation of the Windows is the only answer, but too bad I am not authorised to do a clean wipe on the work laptop. Too much works and paperwork involved. Haha...

OK, I made a huge discovery today. My FF in Private Browsing mode is not Freezing at all. I have tried clearing all my cookies, stored data and cache. Will keep you all update if that helps in normal mode. Cheers!

Switching back to normal mode after clearing all history,cache and cookies does not help. Very odd. Any pointers?

Try to disable hardware acceleration in Firefox.

• Tools > Options > Advanced > General > Browsing: "Use hardware acceleration when available"
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

• https://hacks.mozilla.org/2010/09/hardware-acceleration/

Do a malware check with some malware scanning programs on the Windows computer.
You need to scan with all programs because each program detects different malware.

Make sure that you update each program to get the latest version of their databases before doing a scan.

• Malwarebytes' Anti-Malware:
  http://www.malwarebytes.org/mbam.php
• SuperAntispyware:
  http://www.superantispyware.com/
• Microsoft Safety Scanner:
  http://www.microsoft.com/security/scanner/en-us/default.aspx
• Windows Defender: Home Page:
  http://www.microsoft.com/windows/products/winfamily/defender/default.mspx
• Spybot Search & Destroy:
  http://www.safer-networking.org/en/index.html
• Kasperky Free Security Scan:
  http://www.kaspersky.com/security-scan

You can also do a check for a rootkit infection with TDSSKiller.

• http://support.kaspersky.com/viruses/solutions?qid=208280684

See also:

• "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked

I tried private browsing mode with the Flash plugin enabled, and I experienced the same freezes. Disabling the plugin in private mode made the freezes disappear again. So in my case, the private browsing mode has no influence. (And btw, I already cleared my cache and cookies once, before fiddling with the plugins.)

I also tried disabling the hardware acceleration. No succes either.

And I have also run Malwarebytes' Anti-Malware, SuperAntispyware and the scan of Symantec Endpoint Security. No interesting results here, only some tracking cookies. Deleting them showed no effect on the freezes.

Thanks for the help so far.

Create a new profile as a test to check if your current profile is causing the problems.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer some files from an existing profile to the new profile, but be careful not to copy corrupted files.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Cor-el: Tried that before already. Doesn't work... Thanks for the help anyway,

A new profile is meant as a test to see if this is profile related.
A simple can still carry over a problem.
If it isn't caused by your current profile then it can be caused by security software.

You can try a clean reinstall and delete the Firefox program folder before reinstalling a fresh copy of Firefox.

Try to boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.

A possible cause is security software (firewall,anti-virus) that blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.

Remove all rules for Firefox and the plugin-container from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox and the plugin-container process and the updater process.

See:

• https://support.mozilla.org/kb/Server+not+found
• https://support.mozilla.org/kb/Firewalls